Filter.



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PATBNTED SEPT. 1 1905. J, W. HILL.v 9

FILTER.

APPLICATION FILED N0V.48. 1904.

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No. 800,107. PATENTED SEPT. 19, 1905.'

J. W. 1111111. v

FILTER.

APPLICATION FILED Nov.

3 SHEETS-SHEET 2.

PATENTE-D SEPT. 19, 1905.

J. W. HILL. y FILTER. APILIUATION FILED NO V. 8. 1904.

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XW ff use in connection with a lilter in which there 1s a body of coarse supporting material upon whlch 1s placed the body of ltering material,

UNITED stir-Ams PATENT OFFICE. y

Specicaton of Letters Patent.

Patented sept. 1 9, 1905.

Application ined Noyember 8,1904.. semi No. 231,919.

To @ZZ whom it may concern/.5

Be it known that I, JOHN W. HILL, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Im prove,-

. ments in Filters, of which the following is a specification.

My invention relates particularly to that,-

class of iilters known as preliminary or roughing lters which prepare very tur:

bid water for iinal treatment in plain sand-l i filters by removing at a comparatively high rate of speed of filtration a large percentage of suspended matter, including the bacteria.

By the use of the preliminary filters .the yield per unit of area of the final filter is materially increased and the eiiiciency improved ata material reduction inthe cost of filtration.

My invention is particularly adapted for the outlet or main collector for the Jiiltered water being below the layer of coarse material and the inlet for water to be Iiltered being above the filtering` material, so that the water will percolate through the body of ltering material and the body of coarse supporting material to the outlet.

The object of my invention is to simultaneously agitate and wash the filtering material only vwithout disturbing the body of coarse supporting material and without the introduction of mechanical stirrers. This object I attain by introducing an independent wash-pipe at the upper surface of the coarse supporting material, as fully described here-` inafter, reference being had to the` accompanying drawings, in which- Figure 1 is a plan view of suiiicient of one f section of a filter to illustrate my invention, the filtering material being removed to expose the wash-pipes and the supporting medium. Fig. 2 is a transverse section on the line 2 2, Fig. 1. Fig. 3 is -a side view, partly in section, of one of the slotted lateral pipes. Fig. 4 is a section on 4the line 4: 4t, Fig. 3, showing the coarse supporting material and the iltering material. Fig. 5 is a section on the line 5 5, Fig. 1; and Fig. 6 is sectional View illustrating a modification.

It will be understood at the outset that my invention is particularly adapted for preliminary iiltering water on a large scale, such as v a public'water-supply, although it can be used in small filters without departing from my invention.

A is the concrete foundation of the filter,

in the present instance having side walls A'. Extending longitudinally at the bottom of the lter is a *projecting` portion A2, inclosing the main, collector or outlet Bfor liltered water. Suitableopenings are provided, which connect the collector with the interior of the filtering-chamber.

C isl a body of coarse material through which the'- water will readily percolate and is spread over the entire bottom of the filter, as

indicated in Fig. 2, for a certain depth, so as to provide a suitable porous support for the filtering material D, having myriads of channels throughwhich the ltered water may iiow to the main collector. The coarse supporting material in the present instance is gravel about twelve yinches in depth, and the gravel ranges in size from two and one-half inches in diameter to a quarter of aninch, and the layer of `filtering material is about thirty inches in depth and consists of coarse sand properly prepared. It will be understood that the figures and dimensions above mentioned may be modified without departing from the essential feature of the invention.

'Mounted at the surface of the coarse supporting material@ are two longitudinallyarranged wash-pipes E E, one on each side of the' center, as clearly shown in the drawings, lalthough the number` of these pipes may be `varied according to the type and dimensions of the filter. The two pipes E E are connected with a main E', and the pipes are provided with suitable valveses, as clearly shown in Fig. 1. One half of each pipe E in the present instanceis embedded within the supporting material C and the other part projects into the bed of ltering material D. Extending laterally from the wash-pipes is a series Ofsr'nall pipes c, having perforations in their vupper surfaces, so as to allow the wash-water to escape from the pipes through the bed of Jiiltering material. These lateral pipes extend over the surfaceof the supporting material,

and the laterals e of one main pipe Ealternate sage ofthe filtered water., I preferably perl forate the pipes by slotting, as indicated at e', Figs. 3 and 4, and close one end byasuitable cap e2 in any manner desired. The v'slots 1n IIO the pipe allow for the passage of a' considerable quantity 'of water without making the openings of such a width as to admit the particles of sand which make up the filtering-bed, and, furthermore, when the wash-water is admitted under pressure it escapes from the pipes in a fiat sheet, which will more readily stir and scour the sand than where the perforations are simply small circular holes.

In the present instance I place a trough F above the bed of filtering material and secure it by brackets f to the walls of the filter. This trough is connected with a suitable sluieeway and is for the purpose of carrying off' the wash-water and the dirt held in suspension from the filtering-chamber, so that when the bed of filtering material settles after being washed there will be very little accumulation of foreign material on the surface of the bed and the operation of filtering can be carried on without having to first prepare the bed after the material is agitated. In order to make the trough F adjustable, I slot the brackets at f for the passage of securingbolts f 2 and make the opening a in the wall of the filter of sufficient depth that the trough can be adjusted, and I fill the opening under the trough with temporary brickwork, as shown in Fig. 5, which can be readily removed when necessary. WhileI have shown the trough F on each side and' at one end of the filtering-chamber, a trough F may be arranged in the center of the chamber, as shown in Fig. 6. In this instance ther trough is suspended from the roof-beams A3 by loops f3, which can be adjusted..

The operation of the filter is as followsz Water is let into the filter until it stands about two feet above the filtering medium and the water flows downward through the layer of supporting material to the effluent-passage. The filtering process is continued until the bed becomes more or less clogged by the intercepted matter in the water. This will be readily ascertained by the loss of head or difference of level of the water in the lter and in the main effluent-pipe, which is indicated by Aa suitable arrangement of tubes or fioats, to which I make no claim in this application. When the loss of head reaches a maximum, then the flow of water to the filter is stopped, the bed of filtering material is drained, and wash-water is then admitted through the pipes and its branches, which will agitate and scrub the particles of sand composing the filteringbed. The agitation and cleansing process is carried on simultaneously through the entire bed of filtering material. The wash-water is forced through the pipes under sufficient pressure to accomplish the result. The water after it passes up through the filtering-bedis conveyed from the filter through the troughs at the side of the filtering-chamber and the foreign matter held in suspension in the water is carried with the water from the filteringchamber. After this cleansing operation has been contin ued for a proper length of time Vthe supply of wash-water is discontinued and the bed is allowed to settle upon the supporting medium, and the water to be filtered is then again introduced and percolafcs through the filtering-bed and through the supporting niaterial to the outlet or effluent main.

It will be seen by the above-described construction that there is an independent supplypipe for the wash-water and that the effluentmain is not used for supplying` the filter with wash-water, it being solely used for the purpose of' carrying off filtered water, and as it is not necessary to cleanse the gravel composing the supliiorting-body this gravel is not' agitated, and consequently always remains in position to properly support the sand filtering-bed. Thus I am enabled with less pressure to properly scrub and agitate the bed of filtering material without disturbing the supporting-bed.

I claim as my invention- 1. The combination in a filter, of a bed of coarse supporting material forming myriads of channels for the escape of filtered water to the outlet, a bed of filtering material above and supported by said bed of' coarse material, an inlet for water to be filtered above the said bed of filtering material, an outlet for filtered water below the supporting-bed, a wash-water-supply system situated entirely below the bed of filtering material and of such extent that the entire bed of filtering material will be washed by water escaping from said supply, and an outlet for the ash-water above the bed of filtering material, substantially as described.

2. The combination in a filter, of a bed of coarse supporting material forming myriads of channels for the escape of filtered water to the outlet, a bed of filtering material above and supported by said bed of coarse material, an inlet for water to be filtered above the said bedvof` filtering material, an outlet for filtered water below the supporting-bed, two longitudinal wash-water-supply pipes having perlforated lateral branches, the branches of one pipe alternating' with those of the other pipe, said wash-water-supply pipes being situated between the bed of coarse material and the bed of filtering material and so arranged that the entire bed of filtering material will be washed by water escaping from said pipes, and an outlet for the wash-water above the bed of filtering material, substantially as described.

3. The combination in a filter, of' a bed of coarse supporting material forming myriads of channels for the escape of filtered water to the outlet, a bed of filtering material above and supported'by said bed of coarse material, an inlet for water to be filtered above the said bed of filtered material, a central outlet for filtered water below the supporting-bed, two longitudinal wash-water-supply pipes situated between the bed of coarse material and the bed IOO lIO

, of filtering material, lateral branches extending from each pipe, said branches being perforated, with an outlet-trough for the Wash-water extending around the walls of the filter and above the bed of filtering material, the

whole being so constructed that the entire bed of filtering material will be washed by'water escaping from the said supply-pipes, substantially as described.

4. The combination in a lilter, of a bed of coarse supporting material forming myriads of channels for the escape of filtered water to the outlet, a bed of ltering material above and supported by said bed of coarse material,

an inlet for water to be ltered above the said bed of filtering material,` an outlet for filtered water below the supporting-bed, a wash-water-supply system'situated entirely belowithe body of filtering material and above the body to this specilication in the presence of two subscribing witnesses.

JOHN W. HILL.'

'- Witnesses:

HENRY C. HILL, JAMES F. MCCRUDDEN. 

